One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(6,7)(9,10)(11,14)(12,17)(13,16)(15,20)(18,22)(19,24)(21,23)(25,26,30,35)(27,33,36,31)(28,32,37,38)(29,34,39,40)(1,2,5,4)(3,7,8,6)(9,10)(11,14)(12,15)(13,16)(17,20)(18,22)(19,23)(21,24)(25,27)(26,31)(28,34)(29,32)(30,36)(33,35)(37,40)(38,39)(1,2,5,4)(3,7,8,6)(10,11)(15,17)(16,18)(23,24)(25,28,30,37)(26,32,35,38)(27,34,36,40)(29,33,39,31)(1,3,5,8)(2,6,4,7)(9,11,14,10)(12,17,20,15)(13,16,22,18)(19,23,21,24)(25,28)(26,32)(27,34)(29,31)(30,37)(33,39)(35,38)(36,40)(1,4,5,2)(3,7,8,6)(9,12,14,20)(10,15,11,17)(13,21,22,19)(16,24,18,23)(25,27)(26,33)(28,34)(29,38)(30,36)(31,35)(32,39)(37,40)(1,3)(2,7)(4,6)(5,8)(9,13,14,22)(10,16,11,18)(12,19,20,21)(15,23,17,24)(25,29,30,39)(26,34,35,40)(27,32,36,38)(28,33,37,31)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.